She hasn’t yet formulated a plot to overthrow her boss, but “I can do his job better than he can,” says Cathy, a 27-year-old marketing coordinator who works in Midtown. The Brooklynite, who has asked us not to use her last name or her employer’s for obvious reasons, claims that she is the driver behind her team’s creative efforts and that they could do “amazing things” if she could only take the lead and her manager wasn’t in the way.

“I should be in charge,” she says.

While Cathy may seem egomaniacal and overconfident, she is hardly alone. Almost 40 percent of workers believe that they can do a better job than their bosses, according to a 10,000-person survey conducted by workplace culture site Comparably.

“It’s not necessarily that these people believe that their managers have fallen down on the job. It’s just that this group of workers, especially millennials, are certain that they are entitled to promotions and that they can best their bosses,” says Jason Nazar, Comparably’s co-founder and CEO.

“Maybe they can, maybe they can’t do a better job,” says workplace therapist Brandon Smith. “But that doesn’t mean you should go maverick,” noting that such attempts usually backfire.

“If you went to your boss’ boss to make a case for yourself, the first thing they would ask is whether you addressed the situation with your boss,” he says, which could lead toward all kinds of uncomfortable scenarios.

Aside from the obvious political implications, it might spotlight your impatience, your understanding of how your company works, and your sense of entitlement.

“Workers, especially less experienced workers, often get frustrated because things aren’t moving faster. What they are missing is that their boss has responsibilities that they don’t, including playing politics and navigating the organization,” says Smith.

One way to understand this is to look at your company as a whole, rather than just your role, suggests Chip Espinoza, co-author of “Managing the Millennials” (Wiley). He suggests that you ask yourself such questions as: What is the culture? Do people get promoted quickly? How fast are decisions made and implemented?

If you think you are going to change that, look around. “The organization shapes the individual more than the individual shapes it,” says Espinoza.

So if you want to get promoted, your best bet is to first figure out how your company works. “Befriend an older worker. Get a knowledge transfer,” he says, noting that every company is riddled with ambiguity and that learning how to deal with that is key to success.

Aligning yourself with your boss’ goals will go a long way too. “Treat him as your No. One customer,” says Smith, noting that setting your manager up for success might help him get promoted and make you the obvious choice to be his successor.

“Be a boss promoter instead of a boss killer,” he says.

One way to get your boss’ job, especially if you really are more qualified for the role, is to “wait it out,” according to James McRae, author of “Sh#t Your Ego Says” (Hay House Press). But that doesn’t mean that you should sit there, twirling your thumbs in the meantime.

“Learn how to sell your ideas,” he says, “because the best ideas in the world won’t matter if you can’t sell them to your team.”

McRae also counsels against an attitude that says, “My boss doesn’t know what he is doing. If I can’t have his job, I’m going to quit.”

If the manager truly does stink, he’ll eventually be weeded out, according to McRae. In the meantime, doing great work will put you in a good position when a replacement is needed. Besides, says McRae, “If you jump ship every time you think you are better than your boss, you won’t get anywhere, because you’ll always be starting over.